Thermal and nuclear power plants use steam condensers for condensation of steam after the energy has been utilized to drive the turbine(s). The steam condensers may be water-cooled or air-cooled. In water-cooled process, water is typically obtained from sources like sea, rivers and lakes. The quantity of water required is quite large and it contains debris like grass, shells, fish, cloth and plastic sheet material. Such debris tends to clog the tubes of the steam condensers, causing reduction in heat transfer, which in turn may affect power generation. The problem of accumulation of debris and the need for periodic removal of debris poses a serious challenge to the power generating plants. To overcome this problem, an automatic debris filter is installed at the inlet of the condenser, which filters and removes suspended particles. Conventional automatic debris filters use different techniques for removing debris. In one such conventional debris filter, a tubular housing and a screen basket are provided, the screen basket being fastened to an inner periphery of housing. In the general arrangement of the debris filter, a debris extraction arm is mounted on the inlet side of the basket and is rotatable with respect to the screen and on its complete surface area.
For dislodging and removing debris clogged on the screen suction arms, which completely closes a segment of the screen and is rotatable to cover the complete screen, another method was adopted in the prior art is to use a debris filter with a rotatable suction arm inside the basket arm along with a jet water spray arrangement positioned outside the screen. In this debris filter the profile of the debris extractor does not facilitate removal of sticky debris from the screen easily. Hence, an additional water spray pump which delivers water at a velocity more than the inlet velocity of water from the clean side of filter is required to reverse the sticky debris from the screen. This arrangement results in additional power consumption for the water spray pump and also makes it more expensive.